Adjustable light for underwater photography

Abstract

An underwater diving light includes efficient cooling of LEDs and other internal electronics by heat transfer to ambient water. The water is in contact with a metallic face plate or puck that conducts heat via contiguous metal from an LED circuit board or LED face plate. Ambient water can enter the assembly to spaces between the face plate and an intermediary plate at the front of a housing to efficiently cool the LEDs and associated electronics. In a high-output form the light can emit 8000 lumens, and in this embodiment the battery is cooled by ambient water. The face plate or puck is interchangeable, for different lighting characteristics.

Description

[0001]This application is a continuation-in-part of application Ser. No. 13 / 373,477, filed Nov. 14, 2011, to be issued Oct. 21, 2014 as U.S. Pat. No. 8,864,326, which claimed benefit of provisional application Ser. No. 61 / 414,873, filed Nov. 17, 2010.BACKGROUND AND SUMMARY OF THE INVENTION[0002]The invention concerns underwater video lighting, and particularly a unit producing a powerful beam from LED sources, with the ability to adjust light filtration by rotation of a front filter ring. The underwater light may produce flood light at about 4000 lumens and weighs less than two pounds.[0003]A number of underwater lighting devices are available for divers, some with rechargeable batteries and some also including flip-down color filters, such as red filters.[0004]When an underwater photographer, including a video photographer, dives below about thirty feet during daylight, virtually all red has been filtered out of the ambient light. Because of the color adjustment (white balance) tha...

AI Technical Summary

Benefits of technology

[0014]In the first and second forms of the invention, the metal core circuit board is connected around its edges to the face plate. Thus all the heat must travel laterally across the metal core circuit board to be conducted away. In a third form of the invention, the face plate assembly is not sealed to the body unit, but instead it has large holes to allow water flow into the cavity between body unit and face plate assembly. The face plate assembly has a large rear cap that encloses the metal core circuit board to protect it from corrosion. This rear cap also has a collared area that extends toward the intermediary plate and creates a sealed volume around the connector pads and connector. Thus the heat path is through the thickness of the metal core circuit board and the thickness of the rear cap, rather than along a greater lateral distance.

[0015]In a fourth form of the invention, the metal core circuit board is allowed to directly contact the water, for even better cooling. This can introduce corrosion on the metal core circuit board, but if the device is properly rinsed in fresh water and dried between uses (typical and customary for this type of equipment) the corrosion is minimal and the heat path is reduced further to just metal core circuit board to water. In this form, the rear cap takes a different form and is just the collar bolted to the central area of the metal core circuit board, to form the sealed volume around the connector. Additional benefits of this form are reduction in overall weight, and increased volume of cooling water inside the head, due to the smaller sealing collar instead of the fully enclosing cap of the third form.

[0016]Another form of the invention that is compatible with any of the four sealing and thermal solutions discussed above, employs a second array of LEDs added to a larger metal core circuit board. The multi-function switch on the body unit provides the user the ability to easily turn on one or the other array of LEDs. The second array can be a different color such as red, can be electromagnetic energy outside the visible spectrum such as infrared or UV light, or can be any wavelengths of light focused by dedicated optics, such that the upper array can provide a wide flood light and the lower array a focused spot beam. The advantage of the clustered arrays is that the blue or red filters held by the rotating filter ring enable use of light either filtered or unfiltered, by rotating the filter ring into various positions.

[0017]Another benefit of the removable front plate is the ability to provide interchangeable face plate assemblies to a user. A user might choose to switch face plates (a) to upgrade to a new brighter set of LEDs, (b) to replace a failed face plate or body unit, (c) to switch between colors or types of single-mode face plate units, for instance spot-only for flood-only, (d) to switch from a single-mode face plate unit to a multi-mode face plate unit such as spot plus flood. The body unit electronics can be designed to recognize the available use modes of the attached face plate unit by a detector circuit, and adjust the type of switching available to increase ease of use.

Problems solved by technology

The tight LED array generates considerable heat, making the LED mounting board and surrounding areas hotter than would be the case if the LEDs were spread around the entire face of the housing.

Opening and closing a pressure seal repeatedly can and does introduce physical damage or dirt and grime to the seal, providing a path to potential flooding and corrosion.

Without proper heat dissipation the drive electronics can overheat and fail.

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